Listen before talk (LBT) failure triggered scheduling request indication

ABSTRACT

Systems, methods, apparatuses, and computer program products for handling a listen before talk (LBT) failure are provided. One method may include performing, by a user equipment, listen before talk (LBT). When the listen before talk (LBT) is successful, the method may include transmitting an intended transmission subsequent to the listen before talk (LBT). When the listen before talk (LBT) is not successful, the method may include transmitting an indication of listen before talk (LBT) failure by transmitting a portion of the intended transmission subsequent to the listen before talk (LBT).

FIELD

Some example embodiments may generally relate to communicationsincluding mobile or wireless telecommunication systems, such as LongTerm Evolution (LTE) or fifth generation (5G) radio access technology ornew radio (NR) access technology, or other communications systems. Forexample, certain example embodiments may generally relate to systemsand/or methods for handling a listen before talk (LBT) failure.

BACKGROUND

Examples of mobile or wireless telecommunication systems may include theUniversal Mobile Telecommunications System (UNITS) Terrestrial RadioAccess Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN(E-UTRAN), LTE-Advanced (LTE-A), MulteFire, LTE-A Pro, and/or fifthgeneration (5G) radio access technology or new radio (NR) accesstechnology. 5G wireless systems refer to the next generation (NG) ofradio systems and network architecture. A 5G system is mostly built on a5G new radio (NR), but a 5G (or NG) network can also build on the E-UTRAradio. It is estimated that NR provides bitrates on the order of 10-20Gbit/s or higher, and can support at least service categories such asenhanced mobile broadband (eMBB) and ultra-reliablelow-latency-communication (URLLC) as well as massive machine typecommunication (mMTC). NR is expected to deliver extreme broadband andultra-robust, low latency connectivity and massive networking to supportthe Internet of Things (IoT). With IoT and machine-to-machine (M2M)communication becoming more widespread, there will be a growing need fornetworks that meet the needs of lower power, low data rate, and longbattery life. The next generation radio access network (NG-RAN)represents the RAN for 5G, which can provide both NR and LTE (andLTE-Advanced) radio accesses. It is noted that, in 5G, the nodes thatcan provide radio access functionality to a user equipment (i.e.,similar to the Node B, NB, in UTRAN or the evolved NB, eNB, in LTE) maybe named next-generation NB (gNB) when built on NR radio and may benamed next-generation eNB (NG-eNB) when built on E-UTRA radio.

SUMMARY

An embodiment is directed to a method that may include performing, by auser equipment, listen before talk (LBT). In response to the listenbefore talk (LBT) being successful, the method includes transmitting anintended transmission subsequent to the listen before talk (LBT). Inresponse to the listen before talk (LBT) not being successful, themethod includes transmitting an indication of listen before talk (LBT)failure by transmitting a portion of the intended transmissionsubsequent to the listen before talk (LBT).

In one embodiment, the method may include receiving configuration ofphysical uplink shared channel (PUSCH) resources from a network node. Incase of dynamic scheduling, the configuration comprises an uplink grant.In case of configured grant transmission, the configuration comprisesconfigured grant (CG) physical uplink shared channel (PUSCH)configuration or activation message.

In an embodiment, the performing comprises performing the listen beforetalk (LBT) prior to transmission on the physical uplink shared channel(PUSCH) resources. In response to the listen before talk (LBT) beingsuccessful, the transmitting comprises transmitting the intendedtransmission on the physical uplink shared channel (PUSCH) resources. Inresponse to the listen before talk (LBT) not being successful, thetransmitting comprises transmitting the portion of the intendedtransmission on the physical uplink shared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting the indication on afirst symbol of the physical uplink shared channel (PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting a demodulationreference signal (DMRS) on the first symbol of the physical uplinkshared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting a demodulationreference signal (DMRS) and uplink shared channel (UL-SCH) resourceelements on the first symbol of the physical uplink shared channel(PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting the indication on asymbol after a first symbol of the physical uplink shared channel(PUSCH) resources.

In one embodiment, the method may include performing another listenbefore talk (LBT) prior to transmitting the indication on a symbol aftera first symbol of the physical uplink shared channel (PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting a demodulationreference signal (DMRS) on a second or later symbol of the physicaluplink shared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises: transmitting a demodulationreference signal (DMRS) on a second or later symbol of the physicaluplink shared channel (PUSCH) resources, and transmitting controlinformation in a same symbol as the demodulation reference signal or anext symbol after the demodulation reference signal. The controlinformation may include information about an energy level detected whenmeasurement was performed for the listen before talk (LBT). In anembodiment, the transmitting of the listen before talk (LBT) failureincludes transmitting a demodulation reference signal (DMRS), where asymbol index for the demodulation reference signal (DMRS) indicates thedetected energy level.

An embodiment is directed to an apparatus, which may include at leastone processor and at least one memory comprising computer program code.The at least one memory and computer program code configured, with theat least one processor, to cause the apparatus at least to perform:performing listen before talk (LBT); in response to the listen beforetalk (LBT) being successful, transmitting an intended transmissionsubsequent to the listen before talk (LBT); and in response to thelisten before talk (LBT) not being successful, transmitting anindication of listen before talk (LBT) failure by transmitting a portionof the intended transmission subsequent to the listen before talk (LBT).

In one embodiment, the at least one memory and computer program code areconfigured, with the at least one processor, to cause the apparatus atleast to perform: receiving a configuration of physical uplink sharedchannel (PUSCH) resources from a network node; in case of dynamicscheduling, the configuration comprises an uplink grant; and in case ofconfigured grant transmission, the configuration comprises configuredgrant (CG) physical uplink shared channel (PUSCH) configuration oractivation message.

In an embodiment, the performing comprises the apparatus performing thelisten before talk (LBT) prior to transmission on the physical uplinkshared channel (PUSCH) resources. In response to the listen before talk(LBT) being successful, the transmitting comprises the apparatustransmitting the intended transmission on the physical uplink sharedchannel (PUSCH) resources. In response to the listen before talk (LBT)not being successful, the transmitting comprises the apparatustransmitting the portion of the intended transmission on the physicaluplink shared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises the apparatus transmitting theindication on a first symbol of the physical uplink shared channel(PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises the apparatus transmitting ademodulation reference signal (DMRS) on the first symbol of the physicaluplink shared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises the apparatus transmitting ademodulation reference signal (DMRS) and uplink shared channel (UL-SCH)resource elements on the first symbol of the physical uplink sharedchannel (PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises the apparatus transmitting theindication on symbol after a first symbol of the physical uplink sharedchannel (PUSCH) resources.

In one embodiment, the at least one memory and computer program code areconfigured, with the at least one processor, to cause the apparatus atleast to perform another listen before talk (LBT) prior to transmittingthe indication on a symbol after a first symbol of the physical uplinkshared channel (PUSCH) resources.

In an embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises the apparatus transmitting ademodulation reference signal (DMRS) on a second or later symbol of thephysical uplink shared channel (PUSCH) resources.

In one embodiment, the transmitting of the indication of the listenbefore talk (LBT) failure comprises: the apparatus transmitting ademodulation reference signal (DMRS) on a second or later symbol of thephysical uplink shared channel (PUSCH) resources, and transmittingcontrol information in a same symbol as the demodulation referencesignal or a next symbol after the demodulation reference signal. Thecontrol information may include information about an energy leveldetected when measurement was performed for the listen before talk(LBT). In an embodiment, the transmitting of the listen before talk(LBT) failure includes transmitting a demodulation reference signal(DMRS), where a symbol index for the demodulation reference signal(DMRS) indicates the detected energy level.

An embodiment is directed to an apparatus that may include means forperforming listen before talk (LBT). In response to the listen beforetalk (LBT) being successful, the apparatus includes means fortransmitting an intended transmission subsequent to the listen beforetalk (LBT). In response to the listen before talk (LBT) not beingsuccessful, the apparatus includes means for transmitting an indicationof listen before talk (LBT) failure by transmitting a portion of theintended transmission subsequent to the listen before talk (LBT).

In one embodiment, the apparatus may include means for receiving anindication or configuration of physical uplink shared channel (PUSCH)resources from a network node.

In an embodiment, in case of dynamic scheduling, the configurationcomprises an uplink grant and, in case of configured grant transmission,the configuration comprises configured grant (CG) physical uplink sharedchannel (PUSCH) configuration or activation message.

In one embodiment, the means for performing comprises means forperforming the listen before talk (LBT) prior to the physical uplinkshared channel (PUSCH) resources.

In an embodiment, when the listen before talk (LBT) is successful, themeans for transmitting comprises means for transmitting the intendedtransmission on the physical uplink shared channel (PUSCH) resources.When the listen before talk (LBT) is not successful, the means fortransmitting comprises means for transmitting the portion of theintended transmission on the physical uplink shared channel (PUSCH)resources.

In one embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting theindication on a first symbol of the physical uplink shared channel(PUSCH) resources.

In an embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting ademodulation reference signal (DMRS) on the first symbol of the physicaluplink shared channel (PUSCH) resources.

In one embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting ademodulation reference signal (DMRS) and uplink shared channel (UL-SCH)resource elements on the first symbol of the physical uplink sharedchannel (PUSCH) resources.

In an embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting theindication on symbol after a first symbol of the physical uplink sharedchannel (PUSCH) resources.

In one embodiment, the apparatus may include means for performinganother listen before talk (LBT) prior to transmitting the indication ona symbol after a first symbol of the physical uplink shared channel(PUSCH) resources.

In an embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting ademodulation reference signal (DMRS) on a second or later symbol of thephysical uplink shared channel (PUSCH) resources.

In one embodiment, the means for transmitting of the indication of thelisten before talk (LBT) failure comprises means for transmitting ademodulation reference signal (DMRS) on a second or later symbol of thephysical uplink shared channel (PUSCH) resources, and means fortransmitting control information in a same symbol as the demodulationreference signal or a next symbol after the demodulation referencesignal. The control information may include information about an energylevel detected when measurement was performed for the listen before talk(LBT). In an embodiment, the means for transmitting of the listen beforetalk (LBT) failure includes means for transmitting a demodulationreference signal (DMRS), where a symbol index for the demodulationreference signal (DMRS) indicates the detected energy level.

An embodiment may be directed to a non-transitory computer readablemedium comprising program instructions stored thereon for performing atleast the following: performing listen before talk (LBT), when thelisten before talk (LBT) is successful, transmitting an intendedtransmission subsequent to the listen before talk (LBT), and when thelisten before talk (LBT) is not successful, transmitting an indicationof listen before talk (LBT) failure by transmitting a portion of theintended transmission subsequent to the listen before talk (LBT).

BRIEF DESCRIPTION OF THE DRAWINGS

For proper understanding of example embodiments, reference should bemade to the accompanying drawings, wherein:

FIG. 1 illustrates an example flow chart of a method, according to anembodiment;

FIG. 2A illustrates one alternative for signaling on PUSCH resources,according to an example embodiment;

FIG. 2B illustrates another alternative for signaling on PUSCHresources, according to an example embodiment;

FIG. 2C illustrates another alternative for signaling on PUSCHresources, according to an example embodiment;

FIG. 2D illustrates another alternative for signaling on PUSCHresources, according to an example embodiment;

FIG. 3A illustrates an example block diagram of an apparatus, accordingto an embodiment; and

FIG. 3B illustrates an example block diagram of an apparatus, accordingto an embodiment.

DETAILED DESCRIPTION

It will be readily understood that the components of certain exampleembodiments, as generally described and illustrated in the figuresherein, may be arranged and designed in a wide variety of differentconfigurations. Thus, the following detailed description of some exampleembodiments of systems, methods, apparatuses, and computer programproducts for handling a listen before talk (LBT) failure, is notintended to limit the scope of certain embodiments but is representativeof selected example embodiments.

The features, structures, or characteristics of example embodimentsdescribed throughout this specification may be combined in any suitablemanner in one or more example embodiments. For example, the usage of thephrases “certain embodiments,” “some embodiments,” or other similarlanguage, throughout this specification refers to the fact that aparticular feature, structure, or characteristic described in connectionwith an embodiment may be included in at least one embodiment. Thus,appearances of the phrases “in certain embodiments,” “in someembodiments,” “in other embodiments,” or other similar language,throughout this specification do not necessarily all refer to the samegroup of embodiments, and the described features, structures, orcharacteristics may be combined in any suitable manner in one or moreexample embodiments.

Additionally, if desired, the different functions or proceduresdiscussed below may be performed in a different order and/orconcurrently with each other. Furthermore, if desired, one or more ofthe described functions or procedures may be optional or may becombined. As such, the following description should be considered asillustrative of the principles and teachings of certain exampleembodiments, and not in limitation thereof.

Certain embodiments described herein may relate to 60 GHz unlicensedfrequency bands and, more specifically, co-channel coexistence. Forexample, an embodiment may relate to 3GPP New Radio (NR) physical layerdesign, such as supporting NR from 52.6 GHz to 71 GHz. Some objectivesof this NR physical layer design may include studying changes to NRusing existing downlink (DL)/uplink (UL) NR waveform to supportoperation between 52.6 GHz and 71 GHz, studying applicable numerologyincluding subcarrier spacing, channel bandwidth (including maximum BW),and their impact to frequency range 2 (FR2) physical layer design tosupport system functionality considering practical radio frequency (RF)impairments, and identifying potential problems to physicalsignal/channels. Further, channel access mechanisms are being studied,taking into account potential interference to/from other nodes, assumingbeam-based operation, in order to comply with the regulatoryrequirements applicable to unlicensed spectrum for frequencies, e.g.,between 52.6 GHz and 71 GHz. It is noted that potential interferenceimpact, if identified, may require interference mitigation solutions aspart of channel access mechanism.

Further objectives for channel access procedures relate to physicallayer procedure(s) including channel access mechanism assuming beambased operation in order to comply with the regulatory requirementsapplicable to unlicensed spectrum for frequencies, e.g., between 52.6GHz and 71 GHz. This may include specifying both LBT and No-LBT relatedprocedures, and for the No-LBT case no additional sensing mechanism isspecified. This may also include specifying, if needed, omni-directionalLBT, directional LBT and receiver assistance in channel access, andenergy detection threshold enhancement.

During a LBT procedure, a gNB/UE assesses the occupancy of a channel.During the channel assessment, the gNB/UE may measure energy on thechannel and compare the result of the measurement against a threshold.If the measured energy is below the threshold, the channel is assessedto be vacant. In addition, a gNB/UE may perform a number of channelassessments during the LBT procedure. If the channel is assessed to bevacant on a determined number of channel assessments, including thelatest channel assessment, the LBT procedures determine that a gNB/UEmay occupy the channel with transmission. This determination that thechannel may be occupied is referred to as LBT being successful. If thechannel is not assessed to be vacant on a determined number of channelassessments, or during the latest channel assessment prior to startingtime of an intended transmission, the LBT procedure determines thatgNB/UE cannot occupy the channel with transmission. In this case, LBT isnot successful. This may also be referred to as a LBT failure. Thedetermined number of channel assessments may be predetermined or randomor a combination of both and may depend, e.g., on the type or variant ofthe LBT procedure.

The regulations for operation on 60 GHz unlicensed spectrum require useof a spectrum sharing or co-channel coexistence mechanism, but do notrequire any specific type of a mechanism. In some regions, separateregulatory requirements are defined for different use cases ordeployments, e.g., for fixed outdoor equipment or point-to-pointcommunications or for indoor-only use. However, the ETSI harmonizedstandard (EN 302 567) that targets, e.g., indoor use and fulfils thecorresponding European regulation for frequency band c2, mandates theuse of LBT. Correspondingly, it has been agreed that NR will supportchannel access with LBT as well as without LBT on 60 GHz. In particular,it has been agreed that, for a gNB/UE to initiate a channel occupancy,both channel access with LBT mechanism(s) and a channel access mechanismwithout LBT are supported. It is left for further study whether LBTmechanisms, such as Omni-directional LBT, directional LBT and receiverassisted LBT type of schemes when channel access with LBT is used.Similarly, it remains for further study if operation restrictions forchannel access without LBT are needed, e.g., compliance withregulations, and/or in presence of ATPC, DFS, long term sensing, orother interference mitigation mechanisms. It is also yet to bedetermined the mechanism and condition(s) to switch between channelaccess with LBT and channel access without LBT (if local regulationallows).

However, there has been a recent effort to introduce, into the ETSIstandard, support for short control signaling (SCS). Short controlsignals, as defined by ETSI, are control and management transmissions,that are not required to undergo LBT procedure, but can instead betransmitted without channel sensing (i.e., without LBT), as long as thetotal duration of SCS transmissions over a 100-ms observation intervaldoes not exceed 10%.

Support for contention-exempt short control signalling transmission in60 GHz band is defined for regions where LBT is required and shortcontrol signaling without LBT is allowed. It should be noted that ifregulations do not allow short control signaling exemption in a regionwhen operating with LBT, operation with LBT for these short controlsignals should be supported. Restrictions to the transmission, such as,on duty cycle (airtime measured over a relatively long period of time),content, TX power, etc. can be discussed when specifications aredeveloped.

Support for short control signals both on DL and UL will be provided,and it has been agreed that contention exempt short control signalingrules can be applicable to the transmission of synchronization signal(SS)/physical broadcast channel (PBCH). For contention exempt shortcontrol signalling based DL transmission of SS/PBCH, furtherconsideration is being given to whether the following signals/channelscan be multiplexed with SS/PBCH block transmission: RMSI PDCCH and RMSIPDSCH; other broadcast PDSCH; PDSCH without user-plane data; PDCCH;CSI-RS; PRS; other signals/channels contained in discovery burst (i.e.,exemption applies to discovery burst). It is noted that total exemptedsignals/channels should meet the restriction of 10% over any 100 msinterval.

Contention exempt short control signaling rules apply to thetransmission of msg1 for the 4-step RACH and MsgA for the 2-step RACHfor all supported subcarrier spacings. In a first alternative (Alt 1),the 10% over any 100 ms interval restriction is applicable to allavailable msg1/msgA resources configured (not limited to the resourcesactually used) in a cell. In a second alternative (Alt 2), the 10% overany 100 ms interval restriction is applicable to the msg1/msgAtransmission from one UE perspective. It is for further study whetherother UL signals/channels can be transmitted with contention exemptshort control signaling rule, such as msg3, SRS, PUCCH, PUSCH withoutuser plain data, etc.

Failures in accessing the channel considerably complicate NR operationon unlicensed spectrum. Especially for UL, an LBT failure can causesignificant delays. For configured grant (CG)-physical uplink sharedchannel (PUSCH), a gNB cannot know if the UE intended to transmitanything on a given resource (but LBT failure prevented thetransmission), or not. The additional delay may be particularlyproblematic as CG-PUSCH may be used to achieve short latency. Forscheduled UL transmissions, the gNB can perform blind decoding of ULtransmission (e.g., demodulation reference signal (DMRS)), andreschedule the data transmission for the UE. However, the gNB cannotknow if the UL transmission was blocked by LBT or if the UE just missedthe UL grant, potentially requiring for lower physical downlink controlchannel (PDCCH) code rate. As will be discussed in detail below, certainexample embodiments described herein may provide methods for mitigatingthe uncertainty associated with LBT failures when operating onunlicensed spectrum.

According to some example embodiments, if a UE fails to transmit PUSCHdue to LBT, it will still transmit an indication of the LBT failure asshort control signaling. The indication may correspond to a schedulingrequest indication, that is, a UE transmitting the indication asks forgNB to provide resources for PUSCH transmission. In some embodiments, itmay also be possible to use another LBT later due to some delay beforethe indication needs to be transmitted.

FIG. 1 illustrates an example flow diagram of a method for LBT failuretriggered scheduling request indication, according to one exampleembodiment. In certain example embodiments, the flow diagram of FIG. 1may be performed by a network entity or network node in a communicationssystem, such as LTE or 5G NR. For instance, in some example embodiments,the network entity performing the method of FIG. 1 may include a UE, SLUE, mobile station, IoT device, UE type of road side unit (RSU), otherdevice, or the like.

As illustrated in the example of FIG. 1 , the method may include, at105, receiving an indication and/or configuration of the PUSCH resourcesto use from a gNB. In an embodiment, the indication may include an ULgrant. For example, in case of dynamic scheduling, the receiving 105 mayinclude receiving an uplink grant. In another embodiment, in case ofconfigured grant transmission, the receiving 105 may include receivingthe CG-PUSCH configuration or activation message.

As further illustrated in the example of FIG. 1 , the method mayinclude, at 110, performing LBT prior to an intended UL transmission. Ifit is determined that the LBT is successful at 115, then the method mayinclude transmitting the PUSCH as normal at 120. If it is determinedthat the LBT is not successful at 115, the method may include, at 125,transmitting, on a portion of the indicated PUSCH resources, anindication of the LBT failure (i.e., intention to transmit PUSCH) usingone of the options described below.

Example embodiments can provide several alternatives for implementingthe LBT failure indication. For instance, in certain embodiments, theindication can be transmitted in the first symbol of the PUSCHallocation.

Alternatively or additionally, in some embodiments, the indication canbe transmitted on a later symbol during the PUSCH allocation (i.e., on asymbol after the first symbol of the PUSCH allocation). This alternativecan allow for more processing time for the UE, but may reduce processingtime available for the gNB. Hence, the symbol location is a compromisebetween the two. In one example embodiment, the second DMRS and/or theCG-UCI may be utilized for transmission of the indication; however, anyother symbol may also be used in certain embodiments. It may bedesirable to avoid coding the transmission again, but in such a case,e.g., the first symbol transmission could be used (DMRS or/and PUSCH).According to some embodiments, the symbol position could also be used toconvey information, such as energy level.

According to certain embodiments, in the case of transmission of theindication on a later symbol during the PUSCH allocation, the UE canalso perform another LBT, rather than use SCS. Since there is more timefor performing the LBT, the second LBT may be more likely to succeedthan the first LBT.

In one embodiment, the indication may comprise front-loaded DMRS, whichmay be transmitted during the first PUSCH symbol. The data resourceelements (REs) in the first symbol may be left empty, hence in gNBreceiver DTX detection can be done for DMRS and data separately andresults be compared. If DMRS is detected but the data is absent, thenLBT failure is detected. FIG. 2A illustrates an example of thisembodiment where the indication is a front-loaded DMRS transmittedduring the first PUSCH symbol.

According to a further embodiment, the indication may comprise thefront-loaded DMRS as well as the UL-SCH resource elements on the samesymbol, which may be the first symbol of the PUSCH transmission. Inother words, in this embodiment, PUSCH transmission may just be droppedafter the first symbol. In this case, both DMRS and PUSCH data can beused for DTX detection thereby improving the performance of thedetection. Also, known data could be used for PUSCH but this maycomplicate coding of the transmission in the UE so it may be preferableto use the intended transmission. FIG. 2B illustrates an example of thisembodiment where the indication includes the front-loaded DMRS and theUL-SCH resource elements transmitted on the first symbol of the PUSCHtransmission.

In a further embodiment, the indication may be comprised in the secondor later (i.e., third) DMRS of the PUSCH allocation transmitted withoutthe associated UL-SCH data. This may allow for more processing time forthe UE to decide exactly what to transmit. FIG. 2C illustrates anexample of this embodiment where the indication includes DMRS and istransmitted on a symbol later than the first symbol of the PUSCHtransmission.

According to a further embodiment, the indication may comprise DMRS,together with control information in the same and/or the next symbol,where the control information may provide information about the energylevel detected when the measurement was done for LBT. Detected energylevel may be useful information for the network because it providesadditional information about the load level in the network. FIG. 2Dillustrates an example of this embodiment in which the indicationincludes a DMRS transmitted on a symbol later than the first symbol ofthe PUSCH transmission, and control information transmitted in the sameor next symbol.

Table 1 depicts another example of detected energy level signallingwhere indication of energy level is done using symbol index of DMRS.Here, it is assumed that symbol indices in the middle of the slot areused to allow processing time for both UE and gNB. In this example,detected energy levels are assuming energy threshold to be −47 dBm(according to ETSI EN 302 567, assuming 2 GHz bandwidth).

TABLE 1 Example of energy level signalling Symbol index for DMRSDetected energy level 5 −47 dBm 6 −44 dBm 7 −41 dBm 8 −38 dBm

FIG. 3A illustrates an example of an apparatus 10 according to anembodiment. In an embodiment, apparatus 10 may be a node, host, orserver in a communications network or serving such a network. Forexample, apparatus 10 may be a network node, a sensing node, satellite,base station, a Node B, an evolved Node B (eNB), 5G Node B or accesspoint, next generation Node B (NG-NB or gNB), TRP, HAPS, integratedaccess and backhaul (IAB) node, and/or a WLAN access point, associatedwith a radio access network, such as a LTE network, 5G or NR. In someexample embodiments, apparatus 10 may be gNB or other similar radionode, for instance.

It should be understood that, in some example embodiments, apparatus 10may be comprised of an edge cloud server as a distributed computingsystem where the server and the radio node may be stand-aloneapparatuses communicating with each other via a radio path or via awired connection, or they may be located in a same entity communicatingvia a wired connection. For instance, in certain example embodimentswhere apparatus 10 represents a gNB, it may be configured in a centralunit (CU) and distributed unit (DU) architecture that divides the gNBfunctionality. In such an architecture, the CU may be a logical nodethat includes gNB functions such as transfer of user data, mobilitycontrol, radio access network sharing, positioning, and/or sessionmanagement, etc. The CU may control the operation of DU(s) over afront-haul interface. The DU may be a logical node that includes asubset of the gNB functions, depending on the functional split option.It should be noted that one of ordinary skill in the art wouldunderstand that apparatus 10 may include components or features notshown in FIG. 3A.

As illustrated in the example of FIG. 3A, apparatus 10 may include aprocessor 12 for processing information and executing instructions oroperations. Processor 12 may be any type of general or specific purposeprocessor. In fact, processor 12 may include one or more ofgeneral-purpose computers, special purpose computers, microprocessors,digital signal processors (DSPs), field-programmable gate arrays(FPGAs), application-specific integrated circuits (ASICs), andprocessors based on a multi-core processor architecture, or any otherprocessing means, as examples. While a single processor 12 is shown inFIG. 3A, multiple processors may be utilized according to otherembodiments. For example, it should be understood that, in certainembodiments, apparatus 10 may include two or more processors that mayform a multiprocessor system (e.g., in this case processor 12 mayrepresent a multiprocessor) that may support multiprocessing. In certainembodiments, the multiprocessor system may be tightly coupled or looselycoupled (e.g., to form a computer cluster).

Processor 12 may perform functions associated with the operation ofapparatus 10, which may include, for example, precoding of antennagain/phase parameters, encoding and decoding of individual bits forminga communication message, formatting of information, and overall controlof the apparatus 10, including processes related to management ofcommunication or communication resources.

Apparatus 10 may further include or be coupled to a memory 14 (internalor external), which may be coupled to processor 12, for storinginformation and instructions that may be executed by processor 12.Memory 14 may be one or more memories and of any type suitable to thelocal application environment, and may be implemented using any suitablevolatile or nonvolatile data storage technology such as asemiconductor-based memory device, a magnetic memory device and system,an optical memory device and system, fixed memory, and/or removablememory. For example, memory 14 can be comprised of any combination ofrandom access memory (RAM), read only memory (ROM), static storage suchas a magnetic or optical disk, hard disk drive (HDD), or any other typeof non-transitory machine or computer readable media, or otherappropriate storing means. The instructions stored in memory 14 mayinclude program instructions or computer program code that, whenexecuted by processor 12, enable the apparatus 10 to perform tasks asdescribed herein.

In an embodiment, apparatus 10 may further include or be coupled to(internal or external) a drive or port that is configured to accept andread an external computer readable storage medium, such as an opticaldisc, USB drive, flash drive, or any other storage medium. For example,the external computer readable storage medium may store a computerprogram or software for execution by processor 12 and/or apparatus 10.

In some embodiments, apparatus 10 may also include or be coupled to oneor more antennas 15 for transmitting and receiving signals and/or datato and from apparatus 10. Apparatus 10 may further include or be coupledto a transceiver 18 configured to transmit and receive information. Thetransceiver 18 may include, for example, a plurality of radio interfacesthat may be coupled to the antenna(s) 15, or may include any otherappropriate transceiving means. The radio interfaces may correspond to aplurality of radio access technologies including one or more of GSM,NB-IoT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identifier(RFID), ultrawideband (UWB), MulteFire, and the like. The radiointerface may include components, such as filters, converters (forexample, digital-to-analog converters and the like), mappers, a FastFourier Transform (FFT) module, and the like, to generate symbols for atransmission via one or more downlinks and to receive symbols (via anuplink, for example).

As such, transceiver 18 may be configured to modulate information on toa carrier waveform for transmission by the antenna(s) 15 and demodulateinformation received via the antenna(s) 15 for further processing byother elements of apparatus 10. In other embodiments, transceiver 18 maybe capable of transmitting and receiving signals or data directly.Additionally or alternatively, in some embodiments, apparatus 10 mayinclude an input and/or output device (I/O device), or an input/outputmeans.

In an embodiment, memory 14 may store software modules that providefunctionality when executed by processor 12. The modules may include,for example, an operating system that provides operating systemfunctionality for apparatus 10. The memory may also store one or morefunctional modules, such as an application or program, to provideadditional functionality for apparatus 10. The components of apparatus10 may be implemented in hardware, or as any suitable combination ofhardware and software.

According to some embodiments, processor 12 and memory 14 may beincluded in or may form a part of processing circuitry/means or controlcircuitry/means. In addition, in some embodiments, transceiver 18 may beincluded in or may form a part of transceiver circuitry/means.

As used herein, the term “circuitry” may refer to hardware-onlycircuitry implementations (e.g., analog and/or digital circuitry),combinations of hardware circuits and software, combinations of analogand/or digital hardware circuits with software/firmware, any portions ofhardware processor(s) with software (including digital signalprocessors) that work together to cause an apparatus (e.g., apparatus10) to perform various functions, and/or hardware circuit(s) and/orprocessor(s), or portions thereof, that use software for operation butwhere the software may not be present when it is not needed foroperation. As a further example, as used herein, the term “circuitry”may also cover an implementation of merely a hardware circuit orprocessor (or multiple processors), or portion of a hardware circuit orprocessor, and its accompanying software and/or firmware. The termcircuitry may also cover, for example, a baseband integrated circuit ina server, cellular network node or device, or other computing or networkdevice.

As introduced above, in certain embodiments, apparatus 10 may be or maybe a part of a network element or RAN node, such as a base station,access point, Node B, eNB, gNB, TRP, HAPS, IAB node, WLAN access point,or the like. In one example embodiment, apparatus 10 may be a gNB orother radio node, or may be a CU and/or DU of a gNB. According tocertain embodiments, apparatus 10 may be controlled by memory 14 andprocessor 12 to perform the functions associated with any of theembodiments described herein. For example, in some embodiments,apparatus 10 may be configured to perform one or more of the processesdepicted in any of the flow charts or signaling diagrams describedherein, such as those illustrated in FIGS. 1-2 , or any other methoddescribed herein. In some embodiments, as discussed herein, apparatus 10may be configured to perform a procedure relating to handling of LBTfailure, for example.

According to an example embodiment, apparatus 10 may be controlled bymemory 14 and processor 12 to transmit an indication or configuration ofPUSCH resources to at least one UE. In case of dynamic scheduling, theindication or configuration may include an uplink grant. In case ofconfigured grant transmission, the indication or configuration mayinclude configured grant (CG) physical uplink shared channel (PUSCH)configuration or activation message.

In an embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to receive an intended transmission, from the at least oneUE, when a LBT performed by the at least one UE is successful. In afurther embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to receive, from the at least one UE, an indication oflisten before talk (LBT) failure by receiving a portion of the intendedtransmission subsequent to the listen before talk (LBT). According toone embodiment, the indication may be received in a first symbol of thePUSCH resources. For example, the indication may be received as or in aDMRS on the first symbol of the PUSCH resources. Additionally oralternatively, UL-SCH REs may be received along with the DMRS in thefirst symbol of the PUSCH resources.

In a further embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to receive the indication in a symbol after or later thanthe first symbol of the PUSCH resources. For example, the indication maybe received as or in a DMRS in a second, third or later symbol of thePUSCH resources. In an embodiment, control information may be receivedin the same symbol as the DMRS or a next symbol after the DMRS. Forinstance, the control information may include information about anenergy level detected when measurement was performed for the listenbefore talk (LBT), as discussed in detail above.

FIG. 3B illustrates an example of an apparatus 20 according to anotherembodiment. In an embodiment, apparatus 20 may be a node or element in acommunications network or associated with such a network, such as a UE,communication node, mobile equipment (ME), mobile station, mobiledevice, stationary device, IoT device, or other device. As describedherein, a UE may alternatively be referred to as, for example, a mobilestation, mobile equipment, mobile unit, mobile device, user device,subscriber station, wireless terminal, tablet, smart phone, IoT device,sensor or NB-IoT device, a watch or other wearable, a head-mounteddisplay (HMD), a vehicle, a drone, a medical device and applicationsthereof (e.g., remote surgery), an industrial device and applicationsthereof (e.g., a robot and/or other wireless devices operating in anindustrial and/or an automated processing chain context), a consumerelectronics device, a device operating on commercial and/or industrialwireless networks, or the like. As one example, apparatus 20 may beimplemented in, for instance, a wireless handheld device, a wirelessplug-in accessory, or the like.

In some example embodiments, apparatus 20 may include one or moreprocessors, one or more computer-readable storage medium (for example,memory, storage, or the like), one or more radio access components (forexample, a modem, a transceiver, or the like), and/or a user interface.In some embodiments, apparatus 20 may be configured to operate using oneor more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G,WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and/or any other radioaccess technologies. It should be noted that one of ordinary skill inthe art would understand that apparatus 20 may include components orfeatures not shown in FIG. 3B.

As illustrated in the example of FIG. 3B, apparatus 20 may include or becoupled to a processor 22 for processing information and executinginstructions or operations. Processor 22 may be any type of general orspecific purpose processor. In fact, processor 22 may include one ormore of general-purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs), field-programmablegate arrays (FPGAs), application-specific integrated circuits (ASICs),and processors based on a multi-core processor architecture, asexamples. While a single processor 22 is shown in FIG. 3B, multipleprocessors may be utilized according to other embodiments. For example,it should be understood that, in certain embodiments, apparatus 20 mayinclude two or more processors that may form a multiprocessor system(e.g., in this case processor 22 may represent a multiprocessor) thatmay support multiprocessing. In certain embodiments, the multiprocessorsystem may be tightly coupled or loosely coupled (e.g., to form acomputer cluster).

Processor 22 may perform functions associated with the operation ofapparatus 20 including, as some examples, precoding of antennagain/phase parameters, encoding and decoding of individual bits forminga communication message, formatting of information, and overall controlof the apparatus 20, including processes related to management ofcommunication resources.

Apparatus 20 may further include or be coupled to a memory 24 (internalor external), which may be coupled to processor 22, for storinginformation and instructions that may be executed by processor 22.Memory 24 may be one or more memories and of any type suitable to thelocal application environment, and may be implemented using any suitablevolatile or nonvolatile data storage technology such as asemiconductor-based memory device, a magnetic memory device and system,an optical memory device and system, fixed memory, and/or removablememory. For example, memory 24 can be comprised of any combination ofrandom access memory (RAM), read only memory (ROM), static storage suchas a magnetic or optical disk, hard disk drive (HDD), or any other typeof non-transitory machine or computer readable media. The instructionsstored in memory 24 may include program instructions or computer programcode that, when executed by processor 22, enable the apparatus 20 toperform tasks as described herein.

In an embodiment, apparatus 20 may further include or be coupled to(internal or external) a drive or port that is configured to accept andread an external computer readable storage medium, such as an opticaldisc, USB drive, flash drive, or any other storage medium. For example,the external computer readable storage medium may store a computerprogram or software for execution by processor 22 and/or apparatus 20.

In some embodiments, apparatus 20 may also include or be coupled to oneor more antennas 25 for receiving a downlink signal and for transmittingvia an uplink from apparatus 20. Apparatus 20 may further include atransceiver 28 configured to transmit and receive information. Thetransceiver 28 may also include a radio interface (e.g., a modem)coupled to the antenna 25. The radio interface may correspond to aplurality of radio access technologies including one or more of GSM,LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, andthe like. The radio interface may include other components, such asfilters, converters (for example, digital-to-analog converters and thelike), symbol demappers, signal shaping components, an Inverse FastFourier Transform (IFFT) module, and the like, to process symbols, suchas OFDMA symbols, carried by a downlink or an uplink.

For instance, transceiver 28 may be configured to modulate informationon to a carrier waveform for transmission by the antenna(s) 25 anddemodulate information received via the antenna(s) 25 for furtherprocessing by other elements of apparatus 20. In other embodiments,transceiver 28 may be capable of transmitting and receiving signals ordata directly. Additionally or alternatively, in some embodiments,apparatus 20 may include an input and/or output device (I/O device). Incertain embodiments, apparatus 20 may further include a user interface,such as a graphical user interface or touchscreen.

In an embodiment, memory 24 stores software modules that providefunctionality when executed by processor 22. The modules may include,for example, an operating system that provides operating systemfunctionality for apparatus 20. The memory may also store one or morefunctional modules, such as an application or program, to provideadditional functionality for apparatus 20. The components of apparatus20 may be implemented in hardware, or as any suitable combination ofhardware and software. According to an example embodiment, apparatus 20may optionally be configured to communicate with apparatus 10 via awireless or wired communications link 70 according to any radio accesstechnology, such as NR.

According to some embodiments, processor 22 and memory 24 may beincluded in or may form a part of processing circuitry or controlcircuitry. In addition, in some embodiments, transceiver 28 may beincluded in or may form a part of transceiving circuitry.

As discussed above, according to some embodiments, apparatus 20 may be aUE, SL UE, relay UE, mobile device, mobile station, ME, IoT deviceand/or NB-IoT device, or the like, for example. According to certainembodiments, apparatus 20 may be controlled by memory 24 and processor22 to perform the functions associated with any of the embodimentsdescribed herein, such as one or more of the operations illustrated in,or described with respect to, FIGS. 1-2 , or any other method describedherein. For example, in an embodiment, apparatus 20 may be controlled toperform a process relating to LBT failure handling, as described indetail elsewhere herein.

In an example embodiment, apparatus 20 may be controlled by memory 24and processor 22 to perform LBT. When the LBT is successful, apparatus20 may be controlled by memory 24 and processor 22 to transmit anintended transmission subsequent to the LBT. When the LBT is notsuccessful, apparatus 20 may be controlled by memory 24 and processor 22to transmit an indication of LBT failure by transmitting a portion ofthe intended transmission subsequent to the LBT.

According to an embodiment, apparatus 20 may be controlled by memory 24and processor 22 to receive an indication or configuration of PUSCHresources from a network node. In case of dynamic scheduling, theindication or configuration may include an uplink grant. In case ofconfigured grant transmission, the indication or configuration mayinclude configured grant (CG) physical uplink shared channel (PUSCH)configuration or activation message. In one embodiment, apparatus 20 maybe controlled by memory 24 and processor 22 to perform the LBT prior tothe physical uplink shared channel (PUSCH) resources. When the LBT issuccessful, apparatus 20 may be controlled by memory 24 and processor 22to the intended transmission on the physical uplink shared channel(PUSCH) resources. When the listen before talk (LBT) is not successful,apparatus 20 may be controlled by memory 24 and processor 22 to transmitthe portion of the intended transmission on the physical uplink sharedchannel (PUSCH) resources.

In one embodiment, apparatus 20 may be controlled by memory 24 andprocessor 22 to transmit the indication of the LBT failure on a firstsymbol of the physical uplink shared channel (PUSCH) resources. Forexample, according to an embodiment, apparatus 20 may be controlled bymemory 24 and processor 22 to transmit the indication of the LBT failureas DMRS on the first symbol of the physical uplink shared channel(PUSCH) resources. As another example, apparatus 20 may be controlled bymemory 24 and processor 22 to transmit the indication of the LBT failureas DMRS and uplink shared channel (UL-SCH) resource elements on thefirst symbol of the physical uplink shared channel (PUSCH) resources.

In a further embodiment, apparatus 20 may be controlled by memory 24 andprocessor 22 to transmit the indication of the LBT failure on a symbolafter the first symbol of the physical uplink shared channel (PUSCH)resources. In an embodiment, apparatus 20 may then be controlled bymemory 24 and processor 22 to perform another or second LBT. Accordingto one embodiment, apparatus 20 may be controlled by memory 24 andprocessor 22 to transmit the indication of the LBT failure as a DMRS ona second, third or later symbol of the physical uplink shared channel(PUSCH) resources. In a further embodiment, apparatus 20 may becontrolled by memory 24 and processor 22 to transmit the indication ofthe LBT failure as a DMRS on a second, third or later symbol of thephysical uplink shared channel (PUSCH) resources, and transmit controlinformation in a same symbol as the DMRS or a next symbol after theDMRS. In one example, the control information may include informationabout an energy level detected when measurement was performed for theLBT.

In some embodiments, an apparatus (e.g., apparatus 10 and/or apparatus20) may include means for performing a method, a process, or any of thevariants discussed herein. Examples of the means may include one or moreprocessors, memory, controllers, transmitters, receivers, and/orcomputer program code for causing the performance of the operations.

In view of the foregoing, certain example embodiments provide severaltechnological improvements, enhancements, and/or advantages overexisting technological processes and constitute an improvement at leastto the technological field of wireless network control and/ormanagement. For example, as discussed in detail above, certainembodiments provide ways to mitigate the uncertainty associated with LBTfailures when operating on unlicensed spectrum. In certain embodiments,for CG-PUSCH, a gNB can obtain timely information that UE has data totransmit. The gNB can then schedule PUSCH faster thereby reducing thelatency caused to the UL traffic, which may potentially be latencysensitive. Since the gNB obtains the information that UE has data totransmit, the gNB can use scheduled transmission instead of waiting forthe next CG transmit allocation. For scheduled UL transmissions, the gNBobtains knowledge that UL transmission was blocked by LBT and UEreceived UL grant correctly. The gNB would need to re-schedule the ULtransmission, but the gNB does not need to adjust PDCCH coding(aggregation level). Accordingly, the use of certain example embodimentsresults in improved functioning of communications networks and theirnodes, such as base stations, eNBs, gNBs, and/or IoT devices, UEs ormobile stations.

In some example embodiments, the functionality of any of the methods,processes, signaling diagrams, algorithms or flow charts describedherein may be implemented by software and/or computer program code orportions of code stored in memory or other computer readable or tangiblemedia, and may be executed by a processor.

In some example embodiments, an apparatus may include or be associatedwith at least one software application, module, unit or entityconfigured as arithmetic operation(s), or as a program or portions ofprograms (including an added or updated software routine), which may beexecuted by at least one operation processor or controller. Programs,also called program products or computer programs, including softwareroutines, applets and macros, may be stored in any apparatus-readabledata storage medium and may include program instructions to performparticular tasks. A computer program product may include one or morecomputer-executable components which, when the program is run, areconfigured to carry out some example embodiments. The one or morecomputer-executable components may be at least one software code orportions of code. Modifications and configurations required forimplementing the functionality of an example embodiment may be performedas routine(s), which may be implemented as added or updated softwareroutine(s). In one example, software routine(s) may be downloaded intothe apparatus.

As an example, software or computer program code or portions of code maybe in source code form, object code form, or in some intermediate form,and may be stored in some sort of carrier, distribution medium, orcomputer readable medium, which may be any entity or device capable ofcarrying the program. Such carriers may include a record medium,computer memory, read-only memory, photoelectrical and/or electricalcarrier signal, telecommunications signal, and/or software distributionpackage, for example. Depending on the processing power needed, thecomputer program may be executed in a single electronic digital computeror it may be distributed amongst a number of computers. The computerreadable medium or computer readable storage medium may be anon-transitory medium.

In other example embodiments, the functionality of example embodimentsmay be performed by hardware or circuitry included in an apparatus, forexample through the use of an application specific integrated circuit(ASIC), a programmable gate array (PGA), a field programmable gate array(FPGA), or any other combination of hardware and software. In yetanother example embodiment, the functionality of example embodiments maybe implemented as a signal, such as a non-tangible means, that can becarried by an electromagnetic signal downloaded from the Internet orother network.

According to an example embodiment, an apparatus, such as a node,device, or a corresponding component, may be configured as circuitry, acomputer or a microprocessor, such as single-chip computer element, oras a chipset, which may include at least a memory for providing storagecapacity used for arithmetic operation(s) and/or an operation processorfor executing the arithmetic operation(s).

Example embodiments described herein may apply to both singular andplural implementations, regardless of whether singular or plurallanguage is used in connection with describing certain embodiments. Forexample, an embodiment that describes operations of a single networknode may also apply to example embodiments that include multipleinstances of the network node, and vice versa.

One having ordinary skill in the art will readily understand that theexample embodiments as discussed above may be practiced with proceduresin a different order, and/or with hardware elements in configurationswhich are different than those which are disclosed. Therefore, althoughsome embodiments have been described based upon these exampleembodiments, it would be apparent to those of skill in the art thatcertain modifications, variations, and alternative constructions wouldbe apparent, while remaining within the spirit and scope of exampleembodiments.

We claim:
 1. A method, comprising: performing, by a user equipment,listen before talk (LBT); in response to the listen before talk (LBT)being successful, transmitting an intended transmission subsequent tothe listen before talk (LBT); in response to the listen before talk(LBT) not being successful, transmitting an indication of listen beforetalk (LBT) failure by transmitting a portion of the intendedtransmission subsequent to the listen before talk (LBT).
 2. The methodof claim 1, comprising: receiving configuration of physical uplinkshared channel (PUSCH) resources from a network node; in case of dynamicscheduling, the configuration comprises an uplink grant; and in case ofconfigured grant transmission, the configuration comprises configuredgrant (CG) physical uplink shared channel (PUSCH) configuration oractivation message.
 3. The method of claim 2, wherein: the performingcomprises performing the listen before talk (LBT) prior to transmissionon the physical uplink shared channel (PUSCH) resources; in response tothe listen before talk (LBT) being successful, the transmittingcomprises transmitting the intended transmission on the physical uplinkshared channel (PUSCH) resources; in response to the listen before talk(LBT) not being successful, the transmitting comprises transmitting theportion of the intended transmission on the physical uplink sharedchannel (PUSCH) resources.
 4. The method of claim 2, wherein: thetransmitting of the indication of the listen before talk (LBT) failurecomprises transmitting the indication on a first symbol of the physicaluplink shared channel (PUSCH) resources.
 5. The method of claim 4,wherein: the transmitting of the indication of the listen before talk(LBT) failure comprises transmitting a demodulation reference signal(DMRS) or transmitting a demodulation reference signal (DMRS) and uplinkshared channel (UL-SCH) resource elements on the first symbol of thephysical uplink shared channel (PUSCH) resources.
 6. The method of claim2, wherein: the transmitting of the indication of the listen before talk(LBT) failure comprises transmitting the indication on symbol after afirst symbol of the physical uplink shared channel (PUSCH) resources. 7.The method of claim 6, comprising: performing another listen before talk(LBT) prior to transmitting the indication on a symbol after a firstsymbol of the physical uplink shared channel (PUSCH) resources.
 8. Themethod of claim 6, wherein: the transmitting of the indication of thelisten before talk (LBT) failure comprises transmitting a demodulationreference signal (DMRS) on a second or later symbol of the physicaluplink shared channel (PUSCH) resources.
 9. The method of claim 6,wherein the transmitting of the indication of the listen before talk(LBT) failure comprises: transmitting a demodulation reference signal(DMRS) on a second or later symbol of the physical uplink shared channel(PUSCH) resources, and transmitting control information in a same symbolas the demodulation reference signal or a next symbol after thedemodulation reference signal, wherein the control information comprisesinformation about an energy level detected when measurement wasperformed for the listen before talk (LBT).
 10. The method of claim 6,wherein the transmitting of the indication of the listen before talk(LBT) failure comprises: transmitting a demodulation reference signal(DMRS), wherein a symbol index for the demodulation reference signal(DMRS) indicates a detected energy level.
 11. An apparatus, comprising:at least one processor; and at least one memory comprising computerprogram code, the at least one memory and computer program codeconfigured, with the at least one processor, to cause the apparatus atleast to perform: performing listen before talk (LBT); in response tothe listen before talk (LBT) being successful, transmitting an intendedtransmission subsequent to the listen before talk (LBT); in response tothe listen before talk (LBT) not being successful, transmitting anindication of listen before talk (LBT) failure by transmitting a portionof the intended transmission subsequent to the listen before talk (LBT).12. The apparatus of claim 11, wherein the at least one memory andcomputer program code are configured, with the at least one processor,to cause the apparatus at least to perform: receiving a configuration ofphysical uplink shared channel (PUSCH) resources from a network node; incase of dynamic scheduling, the configuration comprises an uplink grant;and in case of configured grant transmission, the configurationcomprises configured grant (CG) physical uplink shared channel (PUSCH)configuration or activation message.
 13. The apparatus of claim 12,wherein: the performing comprises performing the listen before talk(LBT) prior to transmission on the physical uplink shared channel(PUSCH) resources; in response to the listen before talk (LBT) beingsuccessful, the transmitting comprises transmitting the intendedtransmission on the physical uplink shared channel (PUSCH) resources; inresponse to the listen before talk (LBT) not being successful, thetransmitting comprises transmitting the portion of the intendedtransmission on the physical uplink shared channel (PUSCH) resources.14. The apparatus of claim 12, wherein: the transmitting of theindication of the listen before talk (LBT) failure comprisestransmitting the indication on a first symbol of the physical uplinkshared channel (PUSCH) resources.
 15. The apparatus of claim 14,wherein: the transmitting of the indication of the listen before talk(LBT) failure comprises transmitting a demodulation reference signal(DMRS) or transmitting a demodulation reference signal (DMRS) and uplinkshared channel (UL-SCH) resource elements on the first symbol of thephysical uplink shared channel (PUSCH) resources.
 16. The apparatus ofclaim 12, wherein: the transmitting of the indication of the listenbefore talk (LBT) failure comprises transmitting the indication onsymbol after a first symbol of the physical uplink shared channel(PUSCH) resources.
 17. The apparatus of claim 16, wherein the at leastone memory and computer program code are configured, with the at leastone processor, to cause the apparatus at least to: perform anotherlisten before talk (LBT) prior to transmitting the indication on asymbol after a first symbol of the physical uplink shared channel(PUSCH) resources.
 18. The apparatus of claim 16, wherein: thetransmitting of the indication of the listen before talk (LBT) failurecomprises transmitting a demodulation reference signal (DMRS) on asecond or later symbol of the physical uplink shared channel (PUSCH)resources.
 19. The apparatus of claim 16, wherein the transmitting ofthe indication of the listen before talk (LBT) failure comprises:transmitting a demodulation reference signal (DMRS) on a second or latersymbol of the physical uplink shared channel (PUSCH) resources, andtransmitting control information in a same symbol as the demodulationreference signal or a next symbol after the demodulation referencesignal, wherein the control information comprises information about anenergy level detected when measurement was performed for the listenbefore talk (LBT).
 20. The apparatus of claim 16, wherein thetransmitting of the indication of the listen before talk (LBT) failurecomprises: transmitting a demodulation reference signal (DMRS), whereina symbol index for the demodulation reference signal (DMRS) indicates adetected energy level.